冻结MJS水泥土强度与冻融特性研究  

Study on the strength and freeze-thaw characteristics of frozen MJS cement soil

作　　者：刘欣 杨平[1] 王怀东 李思齐 LIU Xin;YANG Ping;WANG Huaidong;LI Siqi(College of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China;China Railway sixth survey and Design Institute Group Co.,Ltd.,Tianjin 300308,China)

机构地区：[1]南京林业大学土木工程学院,江苏南京210037 [2]中铁第六勘察设计院集团有限公司,天津300308

出　　处：《铁道科学与工程学报》2020年第12期3088-3096,共9页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51478226);南京地铁集团有限公司科研项目。

摘　　要：以南京地铁7号线中胜站全断面承压含水砂层近穿运营车站工程为背景,通过对其粉细砂层进行冻结MJS水泥土试验研究,探讨MJS水泥土的不同水泥掺量、不同龄期、不同状态(冻结,常温,冻融)对水泥土强度变化与冻胀融沉特性的影响。研究结果表明:MJS水泥掺量条件下水泥土冻胀融沉变形很小;冻结后水泥土强度显著提高,抗压及抗折强度分别提高约2倍和3倍,冻结水泥土抗压强度随掺入比增加增幅由快逐渐变慢,且随龄期增长呈对数规律增大;冻结水泥土抗折强度随掺入比增加先增大后减小,存在一个最大强度掺入比(45%),且随龄期增长呈对数规律减小;冻结水泥土弹性模量随龄期和掺入比增加而增大,并基于试验结果提出用于预测冻结水泥土抗压强度的经验公式。Based on the project of Zhongsheng station of Nanjing Metro Line 7,which is full section pressure bearing water bearing sand layer passing through the operation station,through the test and study of frozen MJS cement soil on its silty fine sand layer,this paper discusses the influence of different cement content,different ages and different states(freezing,normal temperature and freeze-thaw)of MJS cement soil on the strength change and freeze-thaw settlement characteristics of cement soil.The results show that:under the condition of MJS cement content,the frost heave thawing settlement deformation of cement soil is very small;after freezing,the strength of cement soil increases significantly,the compressive strength and flexural strength increase about 2 times and 3 times respectively,and the compressive strength of frozen cement soil increases from fast to slow with the increase of mixing ratio,and increases logarithmically with the increase of age;the flexural strength of frozen cement soil increases first and then decreases with the increase of mixing ratio,and then exists a maximum strength mixing ratio(45%),and decreases logarithmically with the increase of age;the elastic modulus of frozen cement soil increases with the increase of age and mixing ratio,and based on the experimental results,an empirical formula for predicting the compressive strength of frozen cement soil is proposed.

关 键 词：冻结MJS水泥土 强度 冻胀融沉 水泥掺入比 龄期 

分 类 号：TU411[建筑科学—岩土工程]